ITunes - Two Libraries by Mistake on same iMac, How to Amalgamate and Deal with Duplicates?

Question

I'm using iTunes 9.2.1 on a PPC iMac G5 running OS X 10.4.11.
I have previously had lots of problems with a damaged iTunes library: https://discussions.apple.com/thread/2009146?threadID=2009146&stqc=true
As a result of this (and I'm not sure how), all music I have added since I got it working again has been stored in a folder called "iTunes Music" (Macintosh HD:Users:Username:Desktop:iTunes Music) which appeared on the Desktop. I also have various iTunes Library files (plus .itdb and .xml files)  on the Desktop (I didn't put them there, that's just what appeared).
All music added priror to this is in Macintosh HD:Users:Username:Music:iTunes:iTunes Music.
Everything works in iTunes (as you would expect - it just points to the relevant folder).
I would like to amalgamate the two iTuens Music folders and file all the music in the correct place (wherever that may be) - is there a simple way of doing this?
Another problem I have is duplicated music - I  imported into iTunes lots (probably 20+ Gb) of duplicate albums at a higher bitrate than I previously had and deleted the existing lower-bitrate version from iTunes. Unfortunately, I didn't realise that, because of the two iTunes music folders, the older version is still stored in the older folder, even though iTunes isn't using it.
Is there a simple way to identify and remove the older lower-bitrate music from the machine without searching every single album in Spotlight?
I've spent an awfully long time correcting and completing track names, information and artwork in iTunes so I really don't want to lose any of that in the process.
Thanks in advance ...

Answer 1

I totally feel your pain. I too have a similar setup, a G4 running Tiger wherein I ripped my vinyl to a higher bitrate than my CD copies. I have in one of thses threads a script that was written for me that would rummage across the home network and pull down all the lower bitrate copies and move them, but I had a hard drive snafu, ran out of space and never got around to it..
I DO think however, that you can display the bitrate of the files in the list view options within iTunes and sort the files that way, and move the duplicate files you don't want to the trash. From within iTunes.. Let me go fire up the livingroom frankenbox to check..
Yup.. If you use the View Options you can sort through the master list in iTunes by bitrate..
http://imageupper.com/i/?S0300010100011D1344782818223713
Takes a bit to sort out the tracks but it's workable..
As to joining the libraries that you've gotten them cleaned up, you need to drop all the song files into a single folder and let iTunes sort them into the default location. There is a submenu here:
http://imageupper.com/i/?S0500010010011A1344783379227569
http://imageupper.com/i/?S0500010010021A1344783379227569
Good luck!
Deb.